Theoretical study on the cluster–surface interaction: The case of subnanometer Pt–Re clusters supported on MgO(100)

• Published in: Computational materials science 2022-11, Vol.214, p.111697, Article 111697
• Main Authors: Álvarez-García, Andrés, Luque-Ceballos, Jonathan Casildo, Paz-Borbón, Lauro Oliver, Garzón, Ignacio L.
• Format: Article
• Language: English
• Subjects: Basin Hopping-DFT Global optimization; Metal cluster–support interaction; Supported bimetallic clusters; Vibrational properties of supported clusters
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2022.111697

Bimetallic clusters in gas phase display novel physicochemical properties that are different from those present in their pure metal analogs. When bimetallic clusters are deposited on a substrate, such properties may change depending on the type and strength of the metal–support interaction. Here, we report a theoretical study, based on density functional theory (DFT), for sub-nanometer clusters of Pt–Re on the pristine MgO(100) surface, using the Basin-Hopping DFT algorithm to find the global minima. Then, their structural, energetic, electronic, and vibrational properties are calculated, and a comparison between gas- and supported-phase behavior is performed. It is obtained that the MgO(100) surface has a more relevant effect on the structural and vibrational properties of the Pt–Re bimetallic clusters and pure Pt clusters. For example, the metal–metal bond lengths of the supported clusters increase with respect to those observed in gas phase, also giving rise to red shifts in the corresponding vibrational frequencies. On the other hand, the structural and vibrational properties of pure gas- and supported-phase Re clusters are quite similar. These results are consistent with the adsorption energy calculations indicating a strong interaction between Pt–Re clusters and pure Pt clusters with the MgO(100) surface. Moreover, the metal–support interaction leads to a charge transfer from the metal oxide to the metal clusters and to the hybridization of the d- and s-states of the metal atoms with the p-states of the oxygen atoms present in the substrate. This work contributes to the understanding of the role of the support in bimetallic Pt–Re clusters on metal oxides, which would be of potential interest in the design of novel nanocatalysts. [Display omitted] •DFT and the Basin-Hopping algorithm were used to find the global minima of Pt–Re clusters on MgO(100).•The formation of Pt–Re clusters on MgO(100) is governed by the metal–support interaction.•The metal–support interaction leads to charge transfer from the surface to the metal cluster.•The MgO(100) surface changes the structural and vibrational properties of gas phase pure Pt and bimetallic Pt–Re clusters.